Browse

The rationale for this work is to make some sort of sense of the seeming myriad of adaptive explanations for why vertebrate brains vary in size. The role that natural selection has played in brain size has been addressed using the comparative method, which allows identification of evolutionary patterns across species. One starting assumption is that brain size is a useful proxy for intelligence and therefore that large-brained animals are more intelligent than smaller-brained animals. Five classes of selection pressure form the majority of explanations: ecology, technology, innovation, sex, and sociality. After chapters in which I describe the difficulties of measuring both brain size and intelligence (cognition), I address the evidence for each of the five factors in turn, reaching the conclusion that although ecology provides the best explanations for variation in the size of brain regions, none of the factors yet offers a robust and compelling explanation for variation in whole brain size. I end by providing the steps I consider necessary to reach such an explanation, steps that I suggest are feasible, if challenging.

Religions and mythologies from around the world teach that God or gods created humans. Atheist, humanist, and materialist critics, meanwhile, have attempted to turn theology on its head, claiming that religion is a human invention. In this book, E. Fuller Torrey draws on cutting-edge neuroscience research to propose a startling answer to the ultimate question. Evolving Brains, Emerging Gods locates the origin of gods within the human brain, arguing that religious belief is a by-product of evolution. Based on an idea originally proposed by Charles Darwin, Torrey marshals evidence that the emergence of gods was an incidental consequence of several evolutionary factors. Using data ranging from ancient skulls and artifacts to brain imaging, primatology, and child development studies, this book traces how new cognitive abilities gave rise to new behaviors. For instance, autobiographical memory, the ability to project ourselves backward and forward in time, gave Homo sapiens a competitive advantage. However, it also led to comprehension of mortality, spurring belief in an alternative to death. Torrey details the neurobiological sequence that explains why the gods appeared when they did, connecting archaeological findings including clothing, art, farming, and urbanization to cognitive developments. This book does not dismiss belief but rather presents religious belief as an inevitable outcome of brain evolution. Providing clear and accessible explanations of evolutionary neuroscience, Evolving Brains, Emerging Gods will shed new light on the mechanics of our deepest mysteries.

This book brings together startling evidence from neuroscience, psychology, and psychiatry to present revolutionary new insights into how our brains enable us to experience the range of sensations and mental states known as feelings. Drawing on own cutting-edge research, the author has identified an area deep inside the mammalian brain—the insular cortex—as the place where interoception, or the processing of bodily stimuli, generates feelings. The book shows how this crucial pathway for interoceptive awareness gives rise in humans to the feeling of being alive, vivid perceptual feelings, and a subjective image of the sentient self across time. The book explains how feelings represent activity patterns in our brains that signify emotions, intentions, and thoughts, and how integration of these patterns is driven by the unique energy needs of the hominid brain. It describes the essential role of feelings and the insular cortex in such diverse realms as music, fluid intelligence, and bivalent emotions, and relates these ideas to the philosophy of William James and even to feelings in dogs. The book is also a compelling insider's account of scientific discovery, one that takes readers behind the scenes as the astonishing answer to this neurological puzzle is pursued and pieced together from seemingly unrelated fields of scientific inquiry. This book will fundamentally alter the way that neuroscientists and psychologists categorize sensations and understand the origins and significance of human feelings.

Sensory Transduction provides a thorough and easily accessible introduction to the mechanisms that each of the different kinds of sensory receptor cell uses to convert a sensory stimulus into an electrical response. Beginning with an introduction to methods of experimentation, sensory specializations, ion channels, and G-protein cascades, it provides up-to-date reviews of all of the major senses, including touch, hearing, olfaction, taste, photoreception, and the “extra” senses of thermoreception, electroreception, and magnetoreception. By bringing mechanisms of all of the senses together into a coherent treatment, it facilitates comparison of ion channels, metabotropic effector molecules, second messengers, and other components of signal pathways that are common themes in the physiology of the different sense organs. With its many clear illustrations and easily assimilated exposition, it provides an ideal introduction to current research for the professional in neuroscience, as well as a text for an advanced undergraduate or graduate-level course on sensory physiology.